The Aging and Alzheimer's Research Center Laboratory Animal Core operates as a shared resource which facilitates, enriches and coordinates animal model studies for four of the five component projects in the Center proposal. This Core has, over previous grant and project periods, developed and maintained barrier-sustained, disease-free colonies of conventional, aged, ultra-aged and lifetime (more 39 months) caloric restricted, neurologically modeled rats in order to reduce data compromising animal variables for new and ongoing studies. We have eliminated infectious agents from all experimental colonies, constructed and renovated new barriered housing areas, established improved environmental conditions for housing behavioral modeled research animals with behavioral testing laboratories contiguous to animal housing rooms. One specific aim of this core component is to continue to provide specialized maintenance of barrier sustained transplant, conventional, caloric-restricted, 6-OHDA modeled and control aged rats. The core will continue to facilitate all aspects of animal model studies as previously developed and implemented. A second specific aim is to provide other core services to Aging Center investigators including comprehensive gross and histopathological evaluations of experimental animals, serological surveillance to document a continuing virus (especially parvovirus) and mycoplasma disease-free status and continuous consultation on laboratory animal genetics, modeling and spontaneous disease evaluations in aged rats. A third specific aim is to maintain and provide Center investigators with nutritionally (caloric) restricted, aged (more 30 months) Fisher 344 rats. In the fourth specific aim, the Core Director will develop a nw, automated data base which will include, monitor and track all experimental animals used in all projects. All project animals will be uniquely identified with implanted with electronic, transponder microchips. This database will be networked to and be accessible by all Center investigators. The Core will coordinate the use of all animals within and between projects in order to maximize the efficiency of animal use and eliminate any potential unnecessary and redundant animal use.